# std::flat_map<Key,T,Compare,KeyContainer,MappedContainer>::rbegin, std::flat_map<Key,T,Compare,KeyContainer,MappedContainer>::crbegin

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< cpp‎ | container‎ | flat map

reverse_iterator rbegin() noexcept; | (1) | (since C++23)
const_reverse_iterator rbegin() const noexcept; | (2) | (since C++23)
const_reverse_iterator crbegin() const noexcept; | (3) | (since C++23)

Returns a reverse iterator to the first element of the reversed `flat_map`. It corresponds to the last element of the non-reversed `flat_map`. If the `flat_map` is empty, the returned iterator is equal to rend().

### Parameters

(none)

### Return value

Reverse iterator to the first element.

### Complexity

Constant.

### Notes

The underlying iterator of the returned reverse iterator is the end iterator. Hence the returned iterator is invalidated if and when the end iterator is invalidated.

### Example

Run this code

    #include <iomanip>
    #include <iostream>
    #include <string_view>
    #include <flat_map>

    int main()
    {
        const std::flat_map<int, std::string_view> coins
        {
            {10, "dime"},
            {100, "dollar"},
            {50, "half dollar"},
            {5, "nickel"},
            {1, "penny"},
            {25, "quarter"}
        }; // initializer entries in name alphabetical order

        std::cout << "US coins in circulation, largest to smallest denomination:\n";
        for (auto it = coins.crbegin(); it != coins.crend(); ++it)
            std::cout << std::setw(11) << it->second << " = ¢" << it->first << '\n';
    }

Output:

    US coins in circulation, largest to smallest denomination:
         dollar = ¢100
    half dollar = ¢50
        quarter = ¢25
           dime = ¢10
         nickel = ¢5
          penny = ¢1

### See also

rendcrend | returns a reverse iterator to the end (public member function)
rbegincrbegin (C++14) | returns a reverse iterator to the beginning of a container or array (function template)

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